scholarly journals Fibrinopeptide a Determination in Clinical Plasma Samples

1977 ◽  
Author(s):  
W.B.J. Gerrits ◽  
O.Th.N. Flier ◽  
J. van der Meer
Keyword(s):  
Pulmonary Embolism ◽  
Disseminated Intravascular Coagulation ◽  
Plasma Levels ◽  
Blood Circulation ◽  
Fibrinopeptide A ◽  
Plasma Samples ◽  
Consumption Coagulopathy ◽  
Elevated Plasma ◽  
Blood Samples

Since the development of radioimmunoassays for fibrinopeptide A (FPA), several studies have been reported on the levels of FPA in plasma from patients.Thus, elevated plasma levels of FPA have been described in disseminated intravascular coagulation, with or without consumption coagulopathy, venous thrombosis or pulmonary embolism. Increased levels of FPA have also been reported during pregnancy and in malignancies. In the majority of these patients, intravenous administration of heparin resulted in a normal FPA level, suggesting that the initially elevated FPA level was caused by the action of thrombin.However, in some patients heparin injection did not lead to normalization of FPA levels. The presence of thrombin in the blood circulation may lead to elevated FPA levels, but also to an accelerated in vitro generation of FPA, which occurs if an anticoagulant without heparin is used. Our studies demonstrate that an enhanced in vitro generation of FPA often occurs in blood samples from patients with elevated FPA levels, but also in samples with a normal FPA level. The mechanism responsible for the latter phenomenon is not clear.Possibly, proteases other than thrombin can lead to the generation of FPA.

The Involvement of Platelets and the Coronary Vasculature in Collagen-Induced Sudden Death in Rabbits

1985 ◽  
Vol 53 (01) ◽  
pp. 070-074 ◽  
Author(s):  
G Mallarkey ◽  
G M Smith
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Platelet Count ◽  
Sudden Death ◽  
Myocardial Ischaemia ◽  
Plasma Levels ◽  
Sodium Citrate ◽  
Plasma Samples ◽  
Calcium Entry Blockers

SummaryThe mechanism of collagen-induced sudden death in rabbits was studied by measuring blood pressure (BP), heart rate, ECG, the continuous platelet count and the plasma levels of thromboxane B2 (TxB2) and 6-keto prostaglandin Fia (6-keto PGF1α). Death was preceded by myocardial ischaemia and a sharp fall in BP which occurred before any fall in platelet count was observed. The calcium entry blockers (CEBs), verapamil, nifedipine and PY 108-068 protected the rabbits from sudden death without any significant effect on the decrease in the platelet count or increase in plasma TxB2 levels. 6-keto PGF1α could not be detected in any plasma samples. Indomethacin and tri-sodium citrate also protected the rabbits but significantly reduced the fall in platelet count and plasma TxB2. In vitro studies on isolated aortae indicated that verapamil non-specifically inhibited vasoconstriction induced by KC1, adrenaline and U46619 (a thromboxane agonist). It is concluded that CEBs physiologically antagonize the vasoconstricting actions of platelet-derived substances and that it is coronary vasoconstriction that is primarily the cause of death.

FACTOR IX CONCENTRATES ARE THROMBOGENIC AT HIGH DOSES IN DOGS

1987 ◽  
Author(s):  
J Ferguson ◽  
J Dawes ◽  
C V Prowse ◽  
P R Foster ◽  
P A Feldman ◽  
...  
Keyword(s):  
Platelet Count ◽  
Fibrinogen Level ◽  
Canine Model ◽  
Factor Ix ◽  
In Vitro Tests ◽  
Fibrinopeptide A ◽  
Blood Products ◽  
Elevated Plasma ◽  
High Doses

A canine model has recently been established to assess the potential thrombogenicity of intravenously infused blood products. Elevated plasma levels of fibrinopeptide A (FpA) were identified as the most sensitive indicator of a thrombogenic response, and this was the only parameter to change significantly when issued batches of factor IX (II + X) concentrate were infused at a dose of 100 iu/kg. After infusion of 200 iu/kg, however, plasma FpA concentrations and FDP titres rose, the APTT was prolonged, and the platelet count and fibrinogen level fell. At this dose, therefore, FIX concentrates which were not identified by in vitro tests as potentially thrombogenic induced a response when infused into dogs.A batch of FIX concentrate which failed the criteria for in vitro thrombogenicity and was therefore not issued for routine use was infused at 100 iu/kg. Plasma FpA levels rose as did the FDP titre, and fibrinogen concentrations fell, but the APTT was only slightly prolonged. The thrombogenic response to 200 iu/kg of issued FIX concentrate was at least as severe as that following infusion of 100 iu/kg of this rejected batch.Thus, there is a threshold dose of FIX concentrate above which a severe thrombogenic response can ensue, and the current in vitro tests may not be a reliable indicator of potential thrombogenicity when FIX concentrates are infused at high doses. This should be taken into account when administering unusually high doses, particularly to patients who may have reduced levels of circulating protease inhibitors.

Association of isocitrate dehydorgenase-1 (IDH-1) mutations with elevated oncometabolite 2-hydroxyglutarate (2HG) in advanced colorectal cancer.

2016 ◽  
Vol 34 (4_suppl) ◽  
pp. 627-627 ◽  
Author(s):  
Nazanin Fallah-Rad ◽  
Philippe L. Bedard ◽  
Lillian L. Siu ◽  
Suzanne Kamel-Reid ◽  
Helen Chow ◽  
...  
Keyword(s):  
Plasma Levels ◽  
Advanced Colorectal Cancer ◽  
Matched Control ◽  
Illumina Miseq ◽  
Tandem Mass ◽  
Plasma Samples ◽  
Elevated Plasma ◽  
Laboratory Plasma ◽  
Kras Mutations ◽  
Archived Samples

627 Background: IDH-1 mutations are common in AML, gliomas, and intrahepatic cholangiocarcinoma. The enzyme product of the IDH-1 R132 variant preferentially catalyzes the NADPH-dependent reduction of alpha-ketoglutarate to the oncometabolite R-2-Hydroxyglutarate (R-2HG), resulting in accumulation of R-2HG, relative to its enantiomer, S-2HG. Elevated plasma levels of 2HG and/or higher ratios of R/S have been observed in AML and intrahepatic cholangiocarinoma, but not in gliomas. Only a few cases of IDH-1/2 mutations have been reported in advanced colorectal cancers (CRC). We investigated plasma levels of 2HG and relative ratios of R/S in CRC patients harboring IDH-1/2mutations. Methods: Between 2012 and 2015, 428 patients with advanced CRC were molecularly profiled through the COMPACT and IMPACT programs at the Princess Margaret Cancer Centre. Tumor DNAs were isolated from FFPE archived samples and genotyped using a customized Sequenom panel or Illumina MiSeq TruSeq Amplicon Cancer Panel in a CLIA-certified laboratory. Plasma samples from patients harboring IDH-1/2mutations and 4 gender/age matched control patients were analyzed for 2HG, R-2HG and S-2HG using HPLC tandem mass spectrometry coupled with a CHIROBIOTIC R column. Results: Of 428 patients with advanced CRC, 4 (0.9%) patients were identified to harbor IDH-1 mutation. No IDH-2 mutations were detected. The variants identified were R132C (2 patients), R132S, and R132H. 3 of 4 patients also harbored KRAS mutations. Patients with IDH-1 mutations had higher levels of 2HG (319 ± 102 ng/ml vs 195 ± 43 ng/ml, p = 0.043). The ratio of R/S were 0.44, 0.75, 1.59, and 2.60 in 4 patients with IDH-1 mutations and 1.3, 0.90, 0.41 and 0.67 in 3 patients without IDH-1mutations. Conclusions: IDH-1 mutations are rare in advanced CRC. 3 of 4 patients in our study had concurrent KRAS mutations. Patients with IDH-1 mutations had higher levels of oncometabolite 2HG compared with controls with no difference in R/S ratio.

Detection of Anti-Thrombopoietin Antibodies in Patients with Immune Thrombocytopenia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4187-4187
Author(s):  
Takashi Satoh ◽  
Koji Miyazaki ◽  
Naoki Shimada ◽  
Koki Nagane ◽  
Tomoya Inukai ◽  
...  
Keyword(s):  
Plasma Levels ◽  
Research Funding ◽  
Immune Thrombocytopenia ◽  
Healthy Controls ◽  
Plasma Samples ◽  
Elevated Plasma ◽  
Competition Assay ◽  
Platelet Production ◽  
Healthy Control ◽  
Control Plasma

Abstract Background: Immune thrombocytopenia (ITP) is an autoimmune disease characterized by the presence of autoantibodies against platelet membrane glycoproteins, which cause the autoantibody-mediated destruction of platelets and impaired platelet production. Thrombopoietin (TPO) binds to its receptor on the surface of hematopoietic stem cells and megakaryocytes and induces their maturation and proliferation. Patients with thrombocytopenia due to aplastic anemia have drastically elevated plasma levels of TPO, whereas patients with ITP have normal or slightly elevated plasma levels of TPO despite their low platelet count. Furthermore, based on the existence of a multitude of autoantibody reactivities in ITP, including antibodies against platelets and TPO receptors, the presence of anti-TPO antibodies in patients with ITP may be suspected. Objective: We developed assay systems to detect plasma anti-TPO antibodies and screen patients with ITP. We examined the clinical characteristics associated with anti-TPO antibodies and their pathogenic roles in patients with ITP. Methods: Plasma anti-TPO antibodies from 101 patients with ITP and 72 healthy controls were measured by enzyme-linked immunosorbent assay (ELISA) using recombinant human TPO (rhTPO) as an antigen. The specificity of anti-TPO antibody reactivity was confirmed by ELISA competition assay. The presence of anti-TPO antibodies was further examined using immunoprecipitation and immunoblotting using rhTPO. To investigate whether anti-TPO antibodies inhibited functional interactions between TPO and TPO receptors, we examined extracellular signal-regulated kinases (ERKs), downstream signals induced by TPO. The binding of TPO to TPO receptors induced the phosphorylation of ERK in TPO receptor-expressing UT-7/TPO cells. Results: The level of anti-TPO antibodies measured by ELISA was significantly greater in the samples from patients with ITP than in those from healthy controls (2.91 ± 3.64 units versus 1.45 ± 0.67 units, P < 0.001). Samples were classified as positive or negative for anti-TPO antibody, as determined by immunoprecipitation and immunoblotting. Thus, the ELISA positive-cutoff value was considered to be the mean plus 3.5 standard deviation (SD) of 72 healthy control plasma samples. Plasma anti-TPO antibodies were detected in twenty-four ITP patients (23.8%), but in none of the healthy controls. By ELISA competition assay, anti-TPO antibody reactivity was inhibited dose-dependently by preincubation of patient plasma with rhTPO. In addition, anti-TPO antibody-positive plasma samples inhibited the phosphorylation of ERK in UT-7/TPO cells. In contrast, healthy control plasma had no inhibitory effect. Furthermore, the number of megakaryocytes was decreased relatively in the anti-TPO antibody-positive ITP patients. There was no difference in the TPO levels in plasma between ITP patients with anti-TPO antibodies and patients without anti-TPO antibodies (63.6 ± 79.7 pg/ml versus 45.2 ± 49.3 pg/ml). Conclusion: Our results have thus demonstrated the presence of anti-TPO autoantibodies in patients with ITP. The ELISA using rhTPO was specific for the detection of anti-TPO antibodies and thus allows their easy and rapid measurement in clinical settings. These findings suggest that functional anti-TPO antibodies cause impaired megakaryocyte proliferation and platelet production in patients with ITP. Disclosures Higashihara: Bristol-Myers Squibb: Research Funding; Baxter: Research Funding; Teijin: Research Funding; Pfizer: Research Funding; Astellas: Research Funding; Yakurt: Honoraria; KyowaHakkoKirin: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Eisai: Honoraria; GlaxoSmithKline: Honoraria, Research Funding; Nippon Shinyaku: Research Funding; Shionogi: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Celgene: Honoraria; Takeda: Honoraria; Janssen　pharma: Honoraria, Research Funding; Alexion: Honoraria; Dainippon Sumitomo: Research Funding; Taisho Tomiyama: Research Funding.

Fluctuations in basal levels and effects of altered nutrition on plasma somatostatin

1982 ◽  
Vol 243 (3) ◽  
pp. R289-R295
Author(s):  
B. C. Hansen ◽  
A. Vinik ◽  
K. L. Jen ◽  
G. P. Schielke
Keyword(s):  
Plasma Levels ◽  
Rhesus Monkeys ◽  
Plasma Samples ◽  
Single Experiment ◽  
Blood Samples ◽  
C Peptide ◽  
Large Fluctuations ◽  
Basal Plasma ◽  
Male Rhesus ◽  
Nutritional Balance

Rapid oscillations in basal plasma levels of insulin, C-peptide, glucagon, and glucose in rhesus monkeys have been reported previously. We now report large minute-to-minute fluctuations in plasma somatostatinlike immunoreactivity (SLI) in undisturbed, chair-adapted, and chronically cannulated male rhesus monkeys. Plasma samples were drawn from eight monkeys at 1- to 2-min intervals for 30-40 min following an overnight fast. Large fluctuations in SLI levels with periods of 4.4-9.4 min/cycle and possibly secondary periods of 14-18 min/cycle with average amplitudes of +/- 23% relative to the respective mean SLI levels were observed both within a single experiment and across monkeys under basal conditions. No consistent relationship was found between SLI fluctuations and that of insulin or glucagon. When portal and central blood samples were drawn precisely simultaneously no consistent portal-central gradient was found. Patterns of fluctuations in central and portal SLI levels were not correlated. Overfeeding significantly increased insulin levels but did not alter SLI levels. After 5 days of food deprivation basal SLI levels were unchanged. These data indicate the need to exercise care in the interpretation of single samples in the measurement of plasma SLI levels. Somatostatin secreted into the blood under basal, unstimulated conditions appears to be unrelated to nutritional balance.

PLASMA LEVELS OF TESTOSTERONE IN BULLS

1978 ◽  
Vol 88 (4) ◽  
pp. 787-792 ◽  
Author(s):  
Anne Sundby ◽  
P. A. Torjesen
Keyword(s):  
Testosterone Level ◽  
Plasma Levels ◽  
Leydig Cells ◽  
Sharp Decrease ◽  
Plasma Testosterone ◽  
Plasma Samples ◽  
Elevated Plasma ◽  
Plasma Testosterone Level ◽  
Testosterone Levels ◽  
Testosterone Production

ABSTRACT Administration of 6000 IU HCG to 4 bulls was followed by an elevation of plasma testosterone lasting for 9–13 days. When HCG administration was repeated, the testosterone response was shortened to 4–6 days in 3 bulls due to the formation of antibodies against HCG. The appearance of HCG antibodies coincided with a sharp decrease in the plasma testosterone level, indicating that Leydig cells have to be under continuous HCG stimulation to maintain increased testosterone production. No antibody against bovine LH was detected in the plasma samples containing antibodies against HCG. In one bull the response following the second HCG injection was similar to the plasma testosterone pattern following the first. No antibodies against HCG were found in this bull. Five bulls received 750 IU HCG twice. Following the period with elevated plasma testosterone levels, subnormal levels were observed after both injections. One injection led to decreased levels without development of antibodies against HCG while the second HCG injection led to subnormal testosterone levels concomitant with measurable antibodies against HCG.

scholarly journals Selected Factors that Affect the Measurement of Plasma Progesterone Concentrations in Pregnant Ewes

1974 ◽  
Vol 27 (6) ◽  
pp. 659 ◽  
Author(s):  
AR Gleeson ◽  
GD Thorburn
Keyword(s):  
Protein Binding ◽  
Diurnal Variation ◽  
Significant Positive Correlation ◽  
Plasma Samples ◽  
Elevated Plasma ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Peripheral Plasma ◽  
Competitive Protein Binding

A competitive protein-binding technique was used to measure progesterone concentrations in the peripheral plasma of pregnant ewes. Neither haemolysis of blood nor thawing of plasma samples affected plasma progesterone concentration. Blood samples should be chilled immediately upon collection but subsequent to centrifugation immediate chilling of the plasma samples is not critical. No consistent diurnal variation in progesterone concentrations was evident but there was large apparently random day-to-day variation in progesterone concentrations for any ewe. Although a significant positive correlation was found between endogenous progesterone and corticosteroid concentrations, the present study failed to correlate experimentally elevated plasma corticosteroid concentrations with progesterone concentrations. Progesterone concentrations varied greatly between ewes at the same stage of pregnancy.

Plasminogen Activation at Low Temperatures in Plasma Samples Gontaining Therapeutic Concentrations of Tissue-Type Plasm i nogen Activator or Other Thrombolytic Agents

1990 ◽  
Vol 64 (01) ◽  
pp. 047-052 ◽  
Author(s):  
D C Rijken ◽  
E Seifried ◽  
M M Barrett-Bergshoeffi ◽  
G Dooijewaard
Keyword(s):  
Thrombolytic Therapy ◽  
Low Temperatures ◽  
Incubation Temperature ◽  
Proteinase Inhibitors ◽  
Tissue Type ◽  
Plasminogen Activation ◽  
Plasma Samples ◽  
Blood Samples ◽  
Type Plasminogen Activator

SummaryIt is known that in vitro plasminogen activation in blood samples taken during thrombolytic therapy with tissue-type plasminogen activator (t-PA) may lead to artefactually low fibrinogen and α2-antiplasmin values. To mimic this phenomenon, pooled normal plasma was supplemented with 2.5 μg/ml t-PA and incubated at various temperatures. The rates of fibrinogen degradation and α2-antiplasmin consumption were most pronounced at 37° C, were less pronounced at 25° C, but surprisingly, did not further decrease at 10° C, 0° C or −8° C. In contrast, when plasma was supplemented with 10° IU/ml urokinase or 30 IU/ml streptokinase, the rates of fibrinogen degradation and α2-antiplasmin consumption gradually decreased with incubation temperature and were negligible at 10° C and lower temperatures. The rate of plasminogen activation also decreased gradually with temperature in mixtures of purified fibrinogen, plasminogeo, α2- antiplasmin and t-PA. These results imply that, in a plasma milieu, additional factors with a stimulatory activity are involved in t-PA-induced plasminogen activation at around 0° C. The abnormally high reaction rate at low temperatures explains in vitro plasminogen activation observed during the processing of t-PA-containing blood samples.In contrast to the activation of plasminogen by t-PA, the slow inhibition of t-PA (2.5 μg/ml) by proteinase inhibitors in plasma could be minimized to a negligible level by keeping the plasma samples at 0° C. This makes it possible to reliably monitor t-PA activity during thrombolytic therapy

scholarly journals Monocyte Secretion of β-Hexosaminidase in Patients With Obstructive Jaundice

HPB Surgery ◽  
1993 ◽  
Vol 7 (1) ◽  
pp. 15-23
Author(s):  
W. G. Jiang ◽  
M. C. A. Puntis
Keyword(s):  
Obstructive Jaundice ◽  
Plasma Levels ◽  
Cell Damage ◽  
Elevated Plasma ◽  
Enzyme Content ◽  
Plasma Enzyme ◽  
Activated Monocytes ◽  
Spontaneous Secretion ◽  
Total Enzyme

Monocyte hydrolases are harmful when secreted inappropriately. In this study we have investigated the levels of one of the hydrolases, β-hexosaminidase in patients with obstructive jaundice. These patients showed markedly elevated plasma levels, and their monocytes show increased spontaneous secretion and total enzyme content. The plasma enzyme levels correlate with monocyte enzyme content as well as bile salt, and bilirubin levels, the high levels may also reflect Kupffer cell damage, as these cells clear the enzyme. Compared with controls monocytes from jaundiced patients show reduced enzyme secretion after PMA stimulation, in vitro, and unchanged secretion after zymozan stimulation. There is a difference between plasma enzyme levels in benign and malignant patients but this does not provide a clear distinction between the two groups. We conclude that patients with obstructive jaundice have increased blood level of β-hexosaminidase, and that activated monocytes partly contribute to this change.

scholarly journals Effect of After-Treatment of Strychnos ligustrina Extract on The Percentage of Parasitemia in Mice Infected with Plasmodium berghei

2020 ◽  
Vol 151 ◽  
pp. 01023
Author(s):  
Umi Cahyaningsih ◽  
Siti Sa’diah ◽  
Wasrin Syafii ◽  
Rita K. Sari ◽  
Harisyah M ◽  
...  
Keyword(s):  
Body Weight ◽  
Plasmodium Berghei ◽  
Blood Circulation ◽  
Blood Smear ◽  
Life Cycles ◽  
Drug Control ◽  
Male Mice ◽  
Antimalarial Treatment ◽  
Blood Samples

Antimalarial treatment is usually given up to 4 days which reduces the number of parasitemia, but malaria can still occur. Therefore, a study to determine the percentage of parasitemia after drug administration is important. Strychnos ligustrina has been investigated in vitro to inhibit the growth of Plasmodium berghei and reduced the number of parasitemia during 4 days of treatment. The purpose of this study was to determine the percentage of parasitemia in mice infected with P. berghei after 4 day treatments with S. ligustrina extract. S. ligustrina was extracted by maceration method using Ethanol 25%, 50%, and 75% (E25, E50, E75, respectively), and Aquades (EA). This study used 91 male mice divided into 5 groups: E25, E50, E70, EA, each extract consisted of 3 doses (200, 400 and 800 mg/kg BW) and Drug Control (DC). For Drug Control (DC) was using a combination of Dihy-droartemisin dose 25 mg/kg BW and piperaquine phosphate dose 197 mg/kg BW. Mice infected with 1x 106 P. berghei intraperitoneally. Blood samples were taken on day 5 after treatment with S. ligustrina extract for 8 days (days 1-8 after treatment). Preparation of blood smear was stained with Giemsa to calculate the percentage of parasitemia by counting the number of infected erythrocytes divided by 500 erythrocytes and multiplied by 100%. The percentages of parasitemia day 7 with 3 kinds of doses of 200, 400, 800 mg/kg body weight in E25 (11,54%, 2.60% and 11.54%, respectively), in E50 (3.44%, 0%, 3.81%, respectively), in E75 (19.25%, 0.73 %, 9.75 %, respectively), in EA (0.77%, 4.48%, 8.67%, respectively) and in DC 2.10%. At the stage of schizogony, which is one of the life cycles of malaria found in the liver, this parasite is not visible in the blood circulation. The results showed that P. berghei was still found in the blood of mice after administration of S. ligustrina extracts up to 4 days in all treatments with different percentages of parasitemia. Based on these results it is recommended that the administration of drugs with S. ligustrina extract as antimalarial drugs for more than 4 days.

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